EP0572305B1 - Improved process for making dry sausages - Google Patents

Description

The present invention relates to an improved method for manufacturing dry sausages using lactic fermentation.

Traditionally, the dry sausages of interest in the context of the present invention are prepared from raw meat, possibly frozen, of bovine, porcine, ovine or avian origin.

• préparation de la pâte par cutterage,
• addition d'un mélange d'ingrédients, d'additifs, de ferments lactiques et microcoques,
• mise en boyau,
• fermentation lactique,
• séchage,
• et éventuellement des étapes classiques de fumage, ensemencement par des moisissures de surface, enrobage ou autres.

The production of this type of dry sausage essentially comprises the following stages:

• dough preparation by cuttering,
• addition of a mixture of ingredients, additives, lactic ferments and micrococci,
• casing,
• lactic fermentation,
• drying,
• and possibly conventional smoking steps, seeding with surface mold, coating or the like.

To obtain sausages of satisfactory quality, it is important that the raw materials are fresh and of low bacteriological contamination. Unfortunately, this is not always the case, especially with regard to meat of avian origin.

The pH is a good indicator of the acceptability of a meat for the manufacture of dry sausages. In general, and for all types of meat, it is preferable that the pH is at most 6.2.

The cutting of the meat takes place at low temperature and the casing must generally be carried out at a maximum temperature of - 4 ° C.

During the cuttering stage, in addition to the lactic ferments, micrococci, salts (sodium chloride, nitrite, nitrate), seasoning are added to the meat paste. (spices), possibly flavor enhancers such as sodium glutamate, an antioxidant which can be vitamin C, and a growth substrate for enzymes, which is generally glucose.

It is during the fermentation stage which follows the casing of the dough that lactic fermentation takes place. The main metabolite resulting from this fermentation is of course lactic acid which intervenes on the organoleptic level and which also allows the reduction of the pH of the dough. This factor is essential to obtain good bacteriological stability of the sausage as well as a satisfactory color and texture. These ferments also produce a whole series of antimicrobial substances which inhibit contaminating germs and pathogenic germs.

In practice, the initial pH of the dough varies from 5.7 to 6.2 and the final pH to be reached after fermentation is between 4.5 and 5.3 depending on the type of sausage.

The lactic ferments used to lower the pH of the dough during maturation are usually mixtures of lactobacilli and pediococci which are mainly acidifying ferments.

The latter are generally associated with flavoring enzymes, for example micrococci and surface molds as well as yeasts which ensure the development of an optimal flavor profile in the sausage.

The action of these ferments takes place during the fermentation stage during which the sausages are stored under controlled humidity and temperature conditions for a few hours to several days. During fermentation, the temperature changes from 22-24 ° C to 16 ° C and the relative humidity from 95 to 75%.

After fermentation, the sausages are dried. This stage lasts from a few days to a few weeks under conditions of temperature and relative humidity also checked. The temperature of this drying is generally between 15 and 20 ° C while the relative humidity is between values varying from 65 to 80%.

It is at the end of fermentation and at the beginning of the drying stage that the development of the characteristic red color of dry sausage begins. This results from the transformation of nitrates into nitrites and then into nitric oxide, the latter compound reacting with myoglobin in meat to form red nitrosomyoglobin which will be transformed into nitrosomyochromogen under acidic conditions.

This red color and its stability over time are important criteria for assessing the quality of a dry sausage.

The dry sausages obtained by such a process are for example pork sausages, beef sausages, salami, chorizzo, turkey sausages.

One of the crucial problems facing the sausage maker is the contamination of meat with common halotolerant germs, often with proteolytic activity, or worse still with pathogenic germs such as golden staphylococci or enterobacteria. Halotolerant proteolytic bacteria degrade meat proteins by producing organoleptically unfavorable metabolites, and pathogens which secrete particularly aggressive toxins are capable of accidentally developing at the start of the manufacturing process when the useful ferments are in the latent phase . These pathogenic germs then secrete enterotoxins which will not be degraded subsequently either by the lactic flora or by any heat treatments. These enterotoxins are the cause of foodborne illness that can be serious, even if the bacteria that cause them may have disappeared or been killed by acidity or the anti-microbial substances secreted by ferments. useful.

In some cases, and this is particularly the case with meat of avian origin, which is leaner than that of pork or beef, the initial pH and water activity conditions are not low enough to prevent development. of these proteolytic or pathogenic microorganisms which, unlike lactic ferments and flavoring ferments such as surface molds, cannot grow at acidic pH.

Sausage producers often find it difficult to source meat of sufficiently low microbial contamination, and this is even more true when it comes to poultry meat such as turkey meat. These meats of poor microbiological quality often have high pH, higher than 5.7. These high pH values increase the risk of multiplication of proteolytic bacteria and even pathogens during the first phase of fermentation. It follows that certain sausages often have to be downgraded not only for reasons of palatability but because they may also be dangerous for the consumer.

It is clear that for practical and economic reasons, producers cannot carry out a bacteriological analysis of all the meats they use, nor carry out a systematic control of the pH of the pieces of meat they use in order to ensure their quality, nor control each production batch with regard to the accidental development of pathogenic bacteria.

It is certain that the hygiene and sanitation measures which have been widely spread in food businesses have greatly contributed to the microbiological improvement of meats, but the fact remains that despite all the precautions taken, the risk of The incident cannot be completely eliminated, especially with regard to fermented products.

It therefore mattered to producers of dry sausages to develop a process allowing them to obtain without firing a blow and this, even with meats whose microbiological quality is not optimal, and in particular with meats whose pH is higher than 5.7, products having however, all the qualities you would expect from a dry sausage in terms of flavor, aroma, color and texture.

It is well known that the growth of the proteolytic bacteria constituting the common microflora of meat can be slowed down by a decrease in pH. This is also the case for the growth of pathogenic germs such as certain golden staphylococci and certain enterobacteria. It is therefore important that the growth of such pathogenic germs is inhibited since sausages are not products which are subjected before their sale to heat treatments making it possible to destroy these germs. It was therefore recommended for these reasons to provide rapid acidification (12 to 18 hours) of the sausages during their fermentation phase, this to prevent the development of the proteolytic or pathogenic flora.

However, the sausage manufacturer cannot remedy the contamination of meat by proteolytic or pathogenic germs by inoculating massive quantities of ferments capable of quickly occupying the ground and thus preventing the growth of these undesirable bacteria. This would indeed generate a prohibitive cost in ferments and would not in any case make their growth less random during the first phase of fermentation.

Attempts have even been made to eliminate these risks due to the growth of proteolytic or pathogenic bacteria by implementing rapid acidification in which the natural lactic acidification caused by the ferments is completely replaced by chemical acidification, using glucono-delta-lactone, hereinafter referred to as GDL.

If the effect obtained on stopping the growth of proteolytic and pathogenic bacteria turns out to be radical, the results obtained are however very disappointing on the technological and organoleptic level. As a result, this technique could not flourish to obtain quality products.

We have therefore seen the appearance of methods for manufacturing dry sausages based on the combined use of lactic ferments and GDL. For example, see page 16 of a document entitled "Effect of bacterial inoculations on characteristics and microbiol flora of dry sausage" ESKO NURMI - Acta agr. alla fennica - n ° 108 - 1966.

• permet la réduction de la durée de fabrication des saucissons,
• limite l'activité des germes pathogènes,
• crée des conditions favorables pour la prédominance rapide des flores de lactobacillus et de levures,
• permet le développement de la consistance désirée dans le saucisson de façon plus rapide,
• mais confère un goût désagréable au saucisson.

It is indicated in this document that the addition of GDL combined with that of ferments:

• allows the reduction of the manufacturing time of sausages,
• limits the activity of pathogenic germs,
• creates favorable conditions for the rapid predominance of lactobacillus and yeast flora,
• allows the desired consistency to develop in the sausage more quickly,
• but gives an unpleasant taste to the sausage.

The document entitled "Salmonellen in frischen Mottwürsion" Udo SCHMIDT Institut für Mikrobiologie, Toxikologie und Histologie der Bundesanstalt für Fleischwirtsch 67 (6) - 1987 - p. 664-714, the document entitled "Effect of pH and Oxygen Tension on Staphylococcal Growth and Enterotoxin Formation in Fermented Sausage" LE BARBER and RH DEIBEL Applied Microbiology, Dec. 1972, p. 891-898, the document entitled "Starter cultures for dry sausages and raw ham Composition and effect" Friedrich-karl LUCKE and Hangsgeorg HECHELMANN Institute of Microbiology, Toxicology and Histology of the Federal Meat Research Institute, Kulmbach, Fleischwirtsch 67 (3) - 1987 - p. 307-314, the document entitled "Inhibiting salmonellae growth in fresh, spreadable Mettwurst (dry sausage eaten relatively fresh) made without sugar "Ulrich SCHILLINGER and Friedrich K. LUCKE Institute of Microbiology, Toxicology and Histology of the Federal Meat Research Institute, Kulmbach Fleischwirtsch 69 (5) - 1989 - p. 879-882, as well that the document entitled "Starter Kulturen und Glucono-delta-lactone (GDL) bei der Rohwurstherstellung". European meeting of meat research workers FP NHNIVAARA 1977 - Vol. 1 - p. 274-288, also describe the joint use of ferments and of GDL in the manufacture of sausages. The document entitled "Rohwurstherstellung mit Starterkulturen im Handwerkbetrieb-Entwicklungsstand und Tendenzen", H. WEBER, Chem. Mikrobiol. Technol. Lebensm. 9, 147-151, 1986, describes a method of manufacturing salamis dry bars recommending the use of GDL to lower the pH in the meat to be treated at the start of fermentation, as well as a variant of the said process which consists of preceding the real fermentation step ized at a temperature of 22-24 ° C by a maturing step done at a temperature of 8 ° C. The document entitled "Cured Pigment and Color Development in Fermented Sausage Containing Glucono-Delta-Lactone", JC ACTON and RL DICK, Journal of Food Protection, Vol. 40, No. 6, 398-401, 1977, describes a process for the manufacture of fermented sausages consisting of direct acidification of the meat by adding GDL and then in conventional lactic fermentation. It appears from these documents that this way of proceeding makes it possible to inhibit the growth of pathogens by rapidly lowering the pH and thus promoting the occupation of the field by lactic starters.

It should however be noted that the document entitled "Production of Italian Dry Salami: Effect of starter culture and chemical acidulation on staphylococcal growth in salami under commercial manufacturing conditions". J. METAXOPOULOS - C. GENNIGEORGIS - MJ FANELLI - C. FRANTI AND E. COSMA. Applied and Environmental Microbiology Nov. 1981 - p. 863-871, which discloses the use of GDL and "starters" shows that not only staphylococci, but also lactic ferments and micrococci can be inhibited by high levels of GDL (see this document, p. 866 - col. 1 and 2). These results are explained by variations in the natural flora of the different types of sausages concerned and by the quantities of GDL used.

A recommendation as to the limitation of the quantity of GDL to be used, also appears in the document NIINIVAARA previously cited. There is also mention of this inhibitory effect in the event that the pH reaches a too low level (<5.0). According to this document, the maximum threshold in GDL is also justified by another reason which is the development of an unpleasant acid taste in sausages. It is also advisable to provide a fermentation / drying temperature below 22 ° C.

Several solutions have been proposed to remedy this organoleptic problem. Thus, KNEISSLER (Chem. Mikrobiol. Technol. Lebensm. 10, 82-85, 1986) has demonstrated that it is the degradation of GDL by lactic ferments which is at the origin of the production of acetic acid, this acid conferring an unacceptable flavor to the sausage. He also indicated that this degradation depends on the nature of the strain involved. It would therefore suffice to choose strains which do not metabolize GDL. However, such strains do not necessarily have the acidification or fermentation qualities required to obtain a quality product.

In the SCHILLINGER document previously cited, it was further advised to store the sausages comprising GDL and ferments at a temperature below 10 ° C to avoid degradation of the residual GDL, after maturation at 20 ° C. But this procedure is obviously not satisfactory.

No technique therefore currently makes it possible to eliminate the drawbacks linked to the use of GDL in the manufacture of dry sausages, despite the extremely favorable impact of this product on the bacteriological quality of the sausages obtained, given that this use is not compatible with obtaining organoleptically satisfactory sausages.

However, it is the merit of the Applicant Company to have overcome this unfavorable prejudice and to have succeeded in developing, after numerous and painstaking research, a process for the manufacture of dry sausages using GDL and ferments lactic, which greatly minimizes the risk of contamination of dry sausages with proteolytic and pathogenic germs, without however harming the organoleptic qualities of the product obtained.

The method for manufacturing dry sausages according to the invention thus consists in measuring the pH of the starting meat paste, in deducing therefrom the amount of GDL to be added to it so as to reach, after hydrolysis of this GDL and before fermentation, a pH between approximately 5.35 and approximately 5.65, mixing the required amount of GDL with the meat paste, and finally practicing, just before fermentation, a step of storing the sausage at a lower temperature or equal to 4 ° C, preferably between 0 and 4 ° C, preferably for a period varying from approximately 12 to 18 hours. During this period, GDL hydrolyzes to gluconic acid, which lowers the pH, and this period is also used to allow the ingredients and additives to migrate and dissolve or evenly distribute in dough.

• préparation de la pâte de viande par cutterage,
• addition d'un mélange d'ingrédients, d'additifs et de ferments lactiques,
• mise en boyau,
• fermentation,
• éventuellement des étapes traditionnelles de fumage, d'ensemencement de surface des saucissons par des moisissures ou levures d'enrobage,

caractérisé en ce qu'on réalise, après l'étape de mise en boyau et avant l'étape de fermentation, une étape de stockage au froid du saucisson à une température inférieure ou égale à 4°C afin de permettre l'hydrolyse de la GDL, la quantité de GDL ajoutée étant déterminée en mesurant le pH de la pâte de viande de départ et en calculant d'après cette mesure la quantité de Glucono-Delta-Lactone (GDL) telle qu'après l'étape de stockage au froid et hydrolyse, et avant l'étape de fermentation, le pH de la pâte soit compris entre 5.35 et 5.65.The present invention therefore relates to a method for manufacturing dry sausages using lactic ferments and GDL and comprising the following steps:

• preparation of the meat paste by cuttering,
• addition of a mixture of ingredients, additives and lactic ferments,
• casing,
• fermentation,
• possibly traditional stages of smoking, of seeding the surface of sausages with molds or coating yeasts,

characterized in that, after the casing step and before the fermentation step, a step of cold storage of the sausage at a temperature below or equal to 4 ° C. is carried out in order to allow the hydrolysis of the GDL, the amount of GDL added being determined by measuring the pH of the starting meat paste and calculating from this measurement the amount of Glucono-Delta-Lactone (GDL) such as after the cold storage step and hydrolysis, and before the fermentation step, the pH of the dough is between 5.35 and 5.65.

Adding GDL Reliably Decreases and controlling the initial pH of the dough, which can be as high as 6.2, to a value between about 5.35 and about 5.65.

In this way, the risk of the development of proteolytic and pathogenic bacteria, common contaminants of meat, is radically eliminated even when the initial pH of the meat is high. The sausage manufacturer is thus assured of a constant and regular microbiological quality of its products. This constitutes appreciable security when you know that a single accident can cause very substantial losses.

Furthermore, this "cold maturation", which allows an acidification of the dough to a pH of approximately 5.35 to approximately 5.65 without allowing pathogenic or proteolytic germs to multiply, subsequently provides a medium allowing optimal growth of homofermentative lactic acid bacteria contained in the ferments.

On the other hand, it has been noted that the existence of this "cold maturation" phase made it possible to eliminate the drawbacks caused by GDL from the point of view of the bad taste of sausages observed when this phase of " cold maturation ".

The method according to the invention also makes it possible to obtain improved dryness of the sausages as well as a frank and stable red coloring. In addition, these phenomena appear very quickly.

The method according to the invention therefore makes it possible to obtain, even with high pH and highly contaminated meats, in complete safety, high quality sausages having no unacceptable organoleptic defects. The sausages obtained by the process according to the invention have in fact a dryness, a color, a flavor, a taste, clearly better than those of the sausages already obtained with GDL but which have not undergone a "cold maturation" stage. "in the presence of this GDL, whether they were manufactured with or without added microbial flora, and clearly better than those obtained in the traditional way without the addition of GDL before lactic fermentation.

The Applicant Company does not have an explanation for this phenomenon which it has highlighted, all the more since it did not particularly fall under the direction of implementing this particular step, costly in time and energy but nevertheless very interesting from the point of view of its eminently favorable repercussions both in terms of contamination risks and in terms of the taste of the sausages thus obtained.

This phenomenon is all the more surprising since the use, in accordance with the invention, of a maturation step at low temperature, which is of course unfavorable to the growth of proteolytic or pathogenic germs, is not either for the growth of lactic ferments. It would therefore have been feared a priori that these conditions would prove harmful for the ferments and in particular for their capacity to develop predominantly when returning to the fermentation temperature.

Finally, it is certainly not the unflattering reputation of the charcuterie products obtained until then using GDL that could have led the skilled person to overcome his doubts and reluctance in a possible approach allowing him to achieve to the invention.

Other advantages deriving from the process according to the invention reside in the relatively low final pH of the sausage which is obtained using the process.

Such a relatively low pH, which is however not correlated with an intense perception of acidity, makes it possible to tolerate a higher water content of the sausages, that is to say a reduced drying, without influencing as much their stability during storage. This results in an economy of drying and a correlative gain in weight which, combined with the absence of products to be downgraded, translate into a significant saving on production costs.

The method according to the invention also finds a quite interesting and advantageous application in the case of the manufacture of low fat sausages. Because of their high water content, these products obtained by traditional methods must indeed be added with significant amounts of salt, this in order to maintain the activity of the water at an acceptable level allowing the conservation of the sausage. The very salty taste of this type of sausage made them difficult to accept. The method according to the invention makes it possible to dispense with the use of large amounts of salt in the manufacture of this type of sausage, their lower pH but without unpleasant organoleptic character allowing them to ensure correct fermentation and preservation in the absence of excessive amounts of salt.

Taking into account the kinetics of acidification of the melee at the storage temperature before maturation, and knowing the initial pH of the melee and that to be reached before maturation, the skilled person can easily determine the amount of GDL to be added to the dough, knowing that one gram of GDL per kilo of scrum lowers the pH of the scrum by about 0.1 units. According to an advantageous variant of the invention, GDL is added to the dough at the same time as the mixture of additive and fermenting ingredients. However, it is generally preferable to add GDL to the dough only just before casing. This avoids any premature gelling of this paste making the rest of the operations more delicate.

As regards the raw material to be used, it obviously depends on the type of sausage considered. It can be pork, beef, mutton, poultry, used alone or in a mixture. Fat is preferably combined with lean meat in proportions which are respectively and more preferably about one third and two thirds, but which can be from one fifth to four fifths in the more specific case of poultry sausages.

In accordance with an advantageous but non-limiting provision of the invention, nitrates and / or nitrites are added to the mixture in the form of a nitrated salt at a concentration of 0.01 to 0.02% and optionally at least one anti- oxidant such as ascorbic acid and this at a rate of 0.01 to 0.1% by weight, as well as spices such as pepper.

The acidifying lactic ferments are preferably chosen from the following species: lactobacilli, pediococci.

The flavoring ferments are chosen in particular from micrococci, staphylococci, yeasts and actynomycetes.

By way of example, mention may be made of the ferments of the DUPLOFERMENTS type sold by the company R. MULLER.

The GDL used is advantageously in the form of crystalline powder.

By way of example, mention may be made of that sold under the registered trademark LYSACTONE by the Applicant Company.

The GDL is added to the dough before fermentation, simultaneously or not simultaneously with the mixture of additive and fermenting ingredients, but preferably just before casing.

The step of storing the sausage or "cold maturation" at a temperature less than or equal to 4 ° C. occurs before fermentation, preferably just after casing.

The duration of this "cold maturation" step is advantageously between 10 and 18 hours. In practice, this corresponds to one night.

The fermentation and drying conditions depend on the type of production considered and the ferments used.

These conditions are in accordance with those commonly used in this technological field. They have been summarized briefly above.

• le fumage,
• l'ensemencement de surface avec des moisissures,
• l'enrobage avec des épices.

The optional steps which can be integrated into the method according to the invention can for example be the following:

• smoking,
• surface seeding with mold,
• coating with spices.

The invention will be better understood with the aid of the following comparative example, which includes the description of an advantageous embodiment of the method according to the invention.

EXAMPLE

To a meaty and fatty base composed of 80% of turkey meat and 20% of pork fat, 3% of nitrite salt, 1% of dextrose were added at the time of the cuttering carried out at a temperature of - 4 ° C. (crystallized glucose), spices (pepper, nutmeg) and a starter composed of lactic ferments and micrococci.

Part of this dough was embossed directly without the addition of GDL before being subjected to "cold maturation".

To another part of this dough, 0.4% GDL was added immediately before embossing. The sausages thus formed with or without GDL were subjected to "cold maturation" for 18 hours at 3 ° C. then were transferred to the fermentation chambers for 4 days and were then dried for 10 days.

Lactic bacteria, enterobacteria and golden staphylococci were counted during these 14 days in both types of sausage.

These results are shown in the attached tables and graphs.

The lactic acid bacteria were counted by counting the colonies appearing on an MRS agar medium after 3 days of incubation at 30 ° C. under anaerobic conditions.

Enterobacteriaceae were counted on VRBG agar medium after 24 hours of aerobic incubation at 30 ° C.

Golden staphylococci were counted on Baird and Parker medium after 2 days of aerobic incubation at 37 ° C.

It is found that GDL has radically prevented the multiplication of enterobacteria and golden staphylococci, thus preventing the secretion of dangerous enterotoxins and the presence of pathogenic bacteria which are the cause of foodborne illness.

We also note that the GDL allowed a much more abundant multiplication of lactic ferments, the number of which is quadrupled compared to the control without GDL.

After fermentation, these sausages were dried and a panel of tasters found that the sausages obtained by the process according to the invention were less acidic although having a pH equal to the control sausages, that they tasted better and that the color stability was much better. TABLE I Sample: GDL sand dry turkey sausage, having undergone "cold ripening" of ± 18 hours at 3 ° C Bact.lact. / g Enterobact. / g S.gold / g pH (1) dough 5,100,000 1,000 100 6.06 (2) 6 p.m. at 3 ° C 7,100,000 30,000 100 5.97 (3) after 1 day. 47,000,000 100 200 4.64 (4) after 2 days. 153,000,000 <10 <100 4.62 (5) after 3 days. 111,000,000 <10 <100 4.68 (6) after 5 days. 118,000,000 <10 <100 4.67 (7) after 7 days. 170,000,000 <10 <100 4.65 (8) after 10 days. 150,000,000 <10 <100 4.63 (9) after 14d. 79,000,000 <10 <100 4.64 Sample: Dry turkey sausage with GDL, having undergone "cold ripening" of ± 18 hours at 3 ° C Bact.lact. / g Enterobact. / g S.gold / g pH (1) dough 5,100,000 1,000 100 6.06 (2) 6 p.m. at 3 ° C 12,000,000 <10 <100 5.59 (3) after 1 day. 130,000,000 <10 <100 4.66 (4) after 2 days. 200,000,000 <10 <100 4.58 (5) after 3 days. 530,000,000 <10 <100 4.65 (6) after 5 days. 160,000,000 <10 <100 4.62 (7) after 7 days. 230,000,000 <10 <100 4.64 (8) after 10 days. 180,000,000 <10 <100 4.63

Figures 1 to 4 respectively represent the evolution of pH, lactic acid bacteria, enterobacteria and golden staphylococci as a function of time.

Claims (7)

1. Process for manufacturing dry sausages using lactic ferments and Glucono-Delta-Lactone (GDL) and comprising:

   - a stage in which meat comminute is prepared by comminution,

   - a stage in which a blend of ingredients, additives, lactic ferments and Glucono-Delta-Lactone (GDL) is added,

   - a stage in which the blend is put into a casing,

   - a fermentation stage,

   - optionally, traditional stages of smoking and seeding the surface of the sausages with moulds or coating yeasts,

   characterized in that, after putting the blend in the casing and before the fermentation stage, a stage is carried out in which the sausage is stored cold at a temperature of less than or equal to 4°C so as to allow hydrolysis of the GDL to take place, the quantity of GDL added being determined by measuring the pH of the starting meat comminute and by calculating from this measurement the quantity of Glucono-Delta-Lactone (GDL) such that after cold storage and hydrolysis, and before the fermentation stage, the pH of the comminute is between 5.35 and 5.65.
2. Process according to claim 1, characterized in that the stage in which the sausage is stored cold is carried out at a temperature of between 0°C and 4°C.
3. Process according to one or other of claims 1 and 2, characterized in that the stage in which the sausage is stored cold lasts from 12 to 18 hours.
4. Process according to any one of claims 1 to 3, characterized in that nitrates and/or nitrites in the form of a nitrite-containing salt, are added to the blend at a concentration of 0.01 to 0.02 % and possibly at least one anti-oxidant agent is added such as ascorbic acid, at the rate of 0.01 to 0.1 % by weight.
5. Process according to any one of claims 1 to 4, characterized in that GDL is used in the form of a crystalline powder.
6. Process according to claim 5, characterized in that the quantity of GDL added in order to reduce the pH of the blend by about 0.1 of a unit is about 1 g per kg of blend.
7. Process according to any one of claims 1 to 6, characterized in that GDL is added to the comminute just before the comminute is put into the casing.

Images